Recent observations in this laboratory have demonstrated the occurrence of non-random chromosome abnormalities in patients with acute non-lymphocytic leukemia (ANLL) and have shown the correlation of cytogenetic abnormalities with clinical response to therapy. In the current proposal, we plan to extend these observations by a coordinated analysis of the following aspects of ANLL: 1) To employ banding techniques to define the incidence and specificity of chromosome abnormalities and to characterize the evolution of karyotypic abnormalities; 2) To define in vitro growth patterns using assay techniques for committed granulocytic (CFU-C) and erythroid (BFU-E) progenitors; 3) To measure specific activities of certain enzymes of nucleic acid metabolism in an effort to determine whether gene mapping and gene dosage effect can be demonstrated in cells with specific chromosomal abnormalities; 4) To establish the exact type of leukemia with cytochemical techniques as well as transmission electron microscopy; 5) To establish the relative significance of specific chromosome abnormalities and/or in vitro growth abnormalities in predicting prognosis of patients with ANLL treated in a single institution in a uniform manner; 6) To compare the above studies in de novo ANLL to those in acute leukemia secondary to other malignancies to define differences in the biologic properties of these types of leukemia.